---
schema_version: "secwatch.filing_event.v1"
accession: "0001628280-26-059191"
form_type: "8-K"
ticker: "WTM"
cik: "0000776867"
company_name: "WHITE MOUNTAINS INSURANCE GROUP LTD"
filed_at: "2026-08-27T12:11:33+00:00"
generated_at: "2026-08-27T12:15:14.436905+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.3
calibrated_materiality_score: 0.3
confidence: "high"
source: SEC EDGAR
---

# White Mountains elects Stephen Klar to board; board expands to 11

## Summary
- Stephen Klar elected director on Aug 26, 2026; board size increased from 10 to 11.
- Klar is former President and Managing Partner of Wellington Management Group LLP.
- Will serve until next annual meeting; receives standard non-employee director compensation.
- CEO Liam Caffrey cited Klar's financial services experience as beneficial to owners.

## SEC filing metadata
- accession: 0001628280-26-059191
- form_type: 8-K
- ticker: WTM
- cik: 0000776867
- company_name: WHITE MOUNTAINS INSURANCE GROUP LTD
- filed_at: 2026-08-27T12:11:33+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.3
- calibrated_materiality_score: 0.3
- confidence: high
- sec_items: 5.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/776867/000162828026059191/0001628280-26-059191-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/776867/000162828026059191/wtm-20260826.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001628280-26-059191
- JSON: https://secwatch.observer/filing/0001628280-26-059191.json
- Plain text: https://secwatch.observer/filing/0001628280-26-059191.txt

## Key facts
- Executive change
  Stephen Klar was elected as director at WHITE MOUNTAINS INSURANCE GROUP LTD.
  - Action: elected
  - Role: director
  source text: On August 26, 2026, the Board of Directors (the “Board”) of White Mountains Insurance Group, Ltd. (the “Company”) elected Stephen Klar as a director of the Company.
  evidence_url: https://www.sec.gov/Archives/edgar/data/776867/000162828026059191/0001628280-26-059191-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.